1. Field of the Invention
The invention generally relates to devices and methods for improving the efficiency of material fragmenting machines and more particularly to feeding mechanisms for controlling the flow of material to a comminuting device.
2. Description of the Related Art
Fragmenting machines or waste recycling machines are designed to splinter and fragment wastes under tremendous impacting forces. Waste is defined herein to comprise any material that requires fragmentation prior to utilization, including, inter alia, wood, biofuel and the like. Operationally, waste materials are fed to a fragmenting zone or grinding chamber by power feeding means. Once the waste materials are within the fragmenting zone or grinding chamber, a powered fragmenting rotor that is rotating at high speed and comprising impacting and shearing teeth is encountered. The resulting impact results in the fragmentation and/or comminution of the waste materials to a desired particle size. Generally, one embodiment of a comminuting or fragmenting machine of the present invention may comprise a rotor rotating at about 1800-2500 r.p.m. Those skilled in the art will readily recognize that other r.p.m. ranges are common, e.g., between about 500 and 2500 r.p.m. The invention described herein is not meant to be limited by r.p.m. ranges and, as a result, applies to any comminuting or fragmenting machine using a power feed mechanism. In all cases, a tremendous force is generated at the point of impact between the waste material and the impacting rotor teeth.
Known power feed wheels may be pivotally mounted on an arm with a single rotational pivot point that allows raising or lowering of the power feed wheel in response to the feed material. Typical power feed wheels consist of a single pair of arms, pivotally mounted on a single rotational axis. This known arrangement results in the power feed wheel moving in a radial pathway that is not concentric with the rotor's circumference. Thus, with known pivotally mounted power feed wheels, the radius of the power feed wheel arms is generally greater than the distance between the rotor axis and the striking surface of the rotor teeth. Moreover, the pivot point is generally higher than the rotor axis, which means that the power feed wheel pivots outwardly away from the rotor as it rises. The result is that the critical distance between the portion of the power feed and the portion of the rotor that are contacting the feed material increases with known power feed lifting systems. This inventive linkage lifting system causes this critical distance to decrease as the power feed rises.
As the distance between the rotor and the power feed wheel increases, the power feed wheel loses desired control over the feed material and fragmenting efficacy diminishes.
Accordingly, there remains a need for a power feed lift device and method that maintains a reasonable distance between the fragmenting rotor and the power feed wheel throughout the power feed's lift path, thus enhancing fragmenting efficiency.
The present invention addresses these needs.